Piston



(No Model.) 2 Sheets Sheet 1. e. WESTINGHOUSB, Jr,

PISTON. N0. 455,029. PatentedJune 30,1891.- LEY llllll illlllllllll 2Sheets-'Sheet 2.

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' Flssf P@.tnted'June 30, 1891.

PISTON.

G. WESTINGHOUSE, Jr.

(No Model.)

A( f JKM WITNEssEs UNITED i STATES PATENT OFFICE.

GEORGE VESTINGIIOUSE, JR., OFPITTSBURG, PENNSYLVANIA.

PISTON.

SPECIFICATION forming part of Letters Patent No.r455,029, dated June 30,1891. Application'led February 16, 1889. Renewed May 13, 1891. SerialNo. 392,607. (No model.)

To all whom it may concern,.-

Beit known that I, GEORGE WEsTINGHoUsE, Jr., a citizen of the UnitedStates, residing at Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented or discovered a certain new and usefulImprovement in Pistons, of which improvement the following is aspecification.

My invention relates to pistons for engines, 1o pumps, or blowers of theclass usually of trunk form, in which a piston-rod is dispensed with andthe connecting-rod is coupled directly to a pin fixed upon the piston,and its object is to provide a piston Vof such type by i 5 theemployment of which wear or lost motion in the connecting-rod bearingsmay be automatically taken up' or compensated for.

The improvement claimed is hereinafter fully set forth.

In the accompanying drawings, Figure 1 is a longitudinal central sectionthrough the cylinder and piston of a compound engine, illustrating anapplication of my invention; Fig. 2, a similar section taken at a rightangle to Fig. l; Figs. 3 and 4, similar sections, re-

spectively, illustrating a modification; Fig. 5, a longitudinal centralsection, on an enlarged scale, through the outer and lower section ofthe head of the piston of Figs. 1 and 2; Fig. 3o 6, a plan or top Viewof the same; Fig. '7, a

longitudinal central section through the innerand upper section of thesame piston; Fig. S, a plan or top view thereof; Fig. 9, a view inelevation of one of the Wrist-pin bolts detached; Fig. 10, a plan view,and Fig. 11 a transverse section, of the upper section of the wrist-pin;and Fig. 12, a plan view, and Fig. 13 a transverse section, of the lowersection of the wrist-pin.

My invention is herein illustrated as applied in the trunk-piston of acompound enpgine, in which the upward stroke is eected by the exertion,initially, of the steam-pressure upon the annular face of thepiston-head between its trunk and the wall of the cylinder in which itworks, and the downward stroke is eected under compound expansion by thepressure of steam exhausted from below the piston upon the entire areaof its upper face, 5o an engine of such character being set forth in aseparate application, Serial No. 300,166, filed of even date herewith byme and by Francis M. Rites jointly, and not being claimed as of mypresent invention.

Referring first to Figs. 1 and 2 and the detailed views, Figs. 5 to 13,inclusive, relating thereto, I provide in the practice of my invention apiston-head which is divided transversely to its axial line into twosections 1 and 2, the upper section 1 being fitted within the lowersection 2, and being provided with proper packing-rings 3 to maintain asteamtight joint between the two. The lower section 2 is fitted to workfreely Within the bore of the cylinder 4, with which it is made tight inthe usual manner by packing-rings 5. An annular open-ended extension ortrunk 6 is formed upon the lower section of the head, within which theconnecting rod by which the piston is coupled directly to the crankpin 8operates. The articulated attachment of the connecting-rod to the pistonis effected through the intermediation of asectional or divided wristpin, the preferred'form of which is, as shown, composed of twoindependent sections 9 and 10, each of which is of its length as forms abearing for the connecting-rod, and the flat sides of which are adaptedto abut in the longitudinal central plane of the wrist-pin parallel withthe upper and lower faces of the piston-head. The lower section 10 ofthe Wrist-pin is'secured to the upper section 1 of the piston-head bybolts l1, having their end portions, which pass through the piston-head1 and wrist-pin section 10, reduced in diameter to form shoulders,against which the connected elements 1 and 10 are firmly clamped by nuts22, enga ging screw-threads cut on the end portions of the bolts. Thebolts 1l t in and pass freely through openings 12 in lugs orguideflanges 13, formed on the inside of the trunk 6 of the lowerpiston-head section and through corresponding openings 14 in end blocks15, formed upon the upper section 9 of the wristpin, which section issecured to the lower section 2 of the piston-head by bolts, which arenot shown, but which pass through openings 17in the flanges 13 of thetrunk, and are tapped into openings 16 in the end blocks 15 of thewrist-pin section 9. It will thus be seen that the two sections of thewrist-pin have the capacity of independent movement semi -cylindrical inform for such portion IOO toward and from the plane of their abuttingfaces, in accordance with the relative movements of the piston-headsections, to which they are, as above described, respectively connected,and, further, that downward pressure upon the upper piston-head section10 will exert corresponding downward pressure upon the lower wrist-pinsection 10, while upward pressure upon the piston will correspondinglyexert upward pressure upon the upper wrist-pin section 9, the tendencyof pressure in either direction being to spread apart or separate theadjacent faces of the wrist-pin sections. As a result of thisconstruction, while compressive strain will, as in the ordinary manner,be exerted upon a connectingrod which is coupled to the sectionalwristpin, in the downward stroke of the piston and tensile strain in theupward stroke, the induced tendency to separation of the wristpinsections will, in the movements of the piston, automatically take up anywear or lost motion between the wrist-pin and the bearings of theconnecting-rod thereon.

In lieu of a single wrist-pin divided into two sections, as abovedescribed, it will be obvious that, if preferred, there may be elnployedas an equivalent construction within the scope of my invention twoindependent wrist-pins, located one above the other, each of saidwrist-pins being connected to one section of the piston-head, and thetwo being subject to constant tendency to separation parallel to theiraxes, as in the construction described and shown.

Vith a connecting-rod of the usual form the automatic adjustment will beeected only at the piston end, manual adjustment at the crank-pin end,which is readily accessible, being necessary, as heretofore. In ordertoextend such adjustment to the crank-pin end of the connecting-rod, thelatter is formed with a main body 7 and an encircling-strap 1S, whichincloses and fits freely around the upper wrist-pin bearing 19 andextends continuously along each side of the body of the rod to its lowercrank-pin bearing 20, to which it is secured by a bolt 2l, both of saidbearings being separate from and uninclosed by the body of the rod. Bysuch construction compressive strain will in each direction of movementof the piston be exerted upon the body of the rod from the lowerwrist-pin section l0, and tensile strain upon the strap 1S from theupper wrist-pin section 9, the eX- ertion of such opposing strains uponthe crank-pin serving to automatically take up or compensate lost motionand wear between the same audits bearings by forcing the latter closelyagainst its periphery through the tendency to longitudinal separation ofthe body and strap of the rod induced by the sectional piston-head andwrist-pin.

The modification shown in Figs. 3 and 4 is designed for use in enginesin which the eX- haust from the cylinder-space above the pistou iseffected into a condenser, and a partial vacuum thereby maintained abovethe upper piston-head section in the upward stroke, in order to maintaina su fiicient degree of pressure upon said section to effect compressivestrain upon the rod through the lower wristpin section. To this end theupper pistonhead section l is wholly inclosed in a space within thelower section 2, which is closed at top by a tight cap 23secured to theupper face of the section 2, an opening being formed in said cap,whichis governed by an inwardlyopening valve 24, pressed up to its seat by aspring 25. In the downward movement of the piston steam enters and fillsthe space within the section 2 above the section l by the valve 24,which on the upward stroke is closed by the spring 25, the steamentrapped within the space above the section 1 exerting downwardpressure u pon said section and upon the connected wrist-pin section lOand connecting-rod body 7 during the upward stroke. lf greater pressureis desired, the supply of steam to the space 'within the section 2 maybe effected by a pipe of small diameter leading thereinto from the lowerannular face of the piston, which, as before stated, is subject tohigh-pressure steam.

I am aware that a compound piston formed in two parts which areindependently counected by separate piston-rod sections to the two partsof a split or divided wrist-pin has been heretofore proposed andillustrated, and such construction, therefore, I do not claim.

I claim as my invention and desire to secure by Letters Patent- 1. Thecombination, in a piston, of a head divided transversely to its axialline intotwo independent sections, one of said sections fitting freelyin a space within the other, a longitudinally-divided wrist-pin, eachsection of which is secured to one of the sections of the head, a tightcap or cover closing the space within the outer piston-head section, andan inwardly-opening valve controlling an opening in said cap,substantially as set forth.

2. The combination, in a piston, of a head divided transversely to itsaxial line into two independent sections, a wrist-pin dividedlongitudinally into two sections, bolts secured at opposite ends to oneof the piston-head sections and to one of the wrist-pin sections, andbolts securing the other wrist-pin section to the other piston-headsection on opposite sides of the bolts first specified, substantially asset forth.

In testimony whereof I have hereunto set my hand.

GEO. VVESTINGIIOUSE, .I R.

Witnesses:

J. SNowDnN BELL, R. H. WHITTLESEY.

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